Radio-Optics Hybrid Single Frequency Network for DTTB: Principle, Technology, and Practice

The digital television terrestrial broadcasting (DTTB) system is one of the most important wireless broadcasting systems, but its indoor coverage performance is not satisfactory enough. The visible light communication (VLC) system works well for indoor scenarios and becomes a quite appealing technology that can realize indoor wireless communications. In this paper, we propose a hybrid system called the radio-optics hybrid single frequency network (SFN) with wide and reliable coverage for DTTB. The current SFN structure of DTTB is maintained, while the optical signal within visible wavelength is adopted to achieve seamless connection between outdoor and indoor. Based on the identical intermediate frequency, the hybrid receiver with antennas and photodiodes can not only receive radio and optical signals individually or simultaneously, but also combine the received signals from different transmitters in the analog/digital domain with various combination methods. The feasibility of the radio-optics hybrid system is verified by the experiment implemented in the laboratory. Furthermore, the proposed hybrid system has great potential to improve other extended applications of DTTB, including positioning, interactivity, scalable video coding, etc.